With an ever increasing number of different sized, shaped and weighted boats due to the increasing popularity of this industry, it is recognized that the trailer must securely support the boat carried thereby, and that the boat hull supporting elements quickly conform to the contour of the hull for proper distribution of the weight of the boat and to avoid localized stresses.
Adequate weight distribution for the massive hulls supported by these modern tandem-type boat trailers provides relative ease of maneuverability during loading and launching, and steady towing characteristics. Conventional means for supporting a boat hull comprises at least a pair of elongated bunk units extended longitudinally of the trailer frame and with each bunk unit spaced equidistantly outwardly of the longitudinal axis of the frame. The bunk units are normally supported fore and aft the frame by a support assembly mounted on a crossbar or to the frame and comprising at least one upright element which is vertically movable by means of a plurality of bolt holes, and having a clamp element at the top for attachment to the bunk unit, quite often in a pivotal manner. The upright element at times comprises a pair of telescopically arranged elements the lowermost fixed in place. Typical bunk supports are shown in U.S. Pat. No. 3,112,245 to MacKusick et al and U.S. Pat. No. 3,993,324 to Carrick.